Project Summary/Abstract Major studies and consensus reports have highlighted that the US health care system has significant shortcomings in delivering care for people who have both chronic medical and mental health conditions. Our study will address challenges in meeting mental health and medical needs of low-income populations by examining aspects of primary care practices that are associated with high quality care for Medicaid beneficiaries with mental health and chronic medical comorbidities. Mental illness (MI), common among adults especially of lower socioeconomic status, frequently co-occurs with chronic physical conditions with comorbidity contributing to poor health outcomes and high service utilization and cost. Prevalence of MI is twice as high in Medicaid beneficiaries as in the general population, and of the nearly one-third of Medicaid beneficiaries with MI, more than half also have chronic medical comorbidity. With nearly one-third of adults who have a mental health visit seeking care solely in primary care practices (PCP), these settings have a chance to address a critical need but often struggle to manage patients with MI and especially those with comorbidities. While researchers have examined the role of PCP organizational factors in delivering care for patients with specific MI or chronic conditions, there is less work on important practice factors for low-resource, high-need, populations such as Medicaid enrollees with comorbidities. As more low-income individuals acquire coverage through Medicaid expansion, there is need to identify factors associated with high-quality care for this population including more research on effectiveness of coordinated care to improve outcomes and reduce cost. Integration of mental and physical health services in primary care settings presents an opportunity to improve care for patients with comorbidities. While shown to achieve positive clinical outcomes and reduced cost, most research has focused on targeted initiatives for specific diseases in large system-based programs. Focusing on New Jersey (NJ), this study will address the lack of examination of state-wide data to analyze how provider efforts to integrate locally outside of large coordinated programs relate to quality of care across diverse PCPs. Drawing on comprehensive NJ Medicaid data over 2014-2016 and linking it to a timely survey of NJ PCPs (Aim 1) that contains rich details about practice organization, we will apply multilevel modeling techniques (Aim 2) to investigate how primary care practice features including practice size, setting and organization, share of patients with mental illness, and co- location of behavioral health provider in PCP might affect established measures of cost, quality of mental and physical health care, and health care services utilization for patients with comorbidities.